SPRING 2010
www.amca.org
IN THIS ISSUE:
• Fan efficiency guides:
How to apply the new standard
• Quantifying the benefits of smoke
dampers in sprinklered buildings
Supplement to Consulting-Specifying Engineer
cse1004_Amca_Cover_ID 1
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spring 2010
⁄ ⁄ InMot i on STAFF
Marian Vambreck, Director of Membership,
Marketing and Communications —
AMCA International, Inc.
n the Fall 2009 issue of AMCA inmotion, I commented that
economists were reporting an uptick in the economy, but it
Amara Rozgus, Senior Editor & Manager
of E-Content, Consulting-Specifying Engineer
would be a year or so before the commercial buildings industry
Leslie Pappas, Manager, Creative Services
felt any impact from it. Well, we’re obviously still in that lag.
Patrick Lynch, Associate Editor
Nonetheless, AMCA continues to work toward improving
available to our customers for improving their processes for
Reed Business Information
2000 Clearwater Drive
Oak Brook, IL 60523
phone: 630-288-8780
fax: 630-288-8782
Trudy Kelly, Assistant to the Publisher
Elena Moeller-Younger, Marketing Director
Michael Rotz, Production Manager
designing, sizing, and selecting air movement and control
systems.
One way AMCA is instrumental to our industry is in the
development of testing standards for the AMCA Certified Ratings Program, which
w w w. a m c a . o r g
not only the products of our members, but the resources
⁄ ⁄ Publ i cati on Serv ices
Jim Langhenry, Publisher
inmotion
I
Michael G. Ivanovich, Editor-in-Chief,
Consulting-Specifying Engineer
A M C A I n t e r n at i o n a l
president’s message
provides engineers, contractors, and owners with the assurance that AMCA-certified
products will perform as expected in the field.
AMCA also develops standards and guidelines that help engineers with the design
and specification of systems. I am excited to report that AMCA Standard 205-10, Energy
Efficiency Classification for Fans, was approved by the AMCA International membership
in February, and that this issue of AMCA inmotion has an in-depth article on how to apply
this standard.
For information on this standard and all AMCA standards and guidelines, and for
⁄ ⁄ B oard o f Di rector s
Art LaPointe, President
Vice President and General Manager
Construction Specialties Inc.
Denis Labelle, Chairman of the Board
Executive Vice President,
T.A. Morrison & Co.
electronic versions of this and other issues of AMCA inmotion, visit AMCA’s Web site at
www.amca.org.
Sincerely,
Michael Barry, Vice President
President
Twin City Fan Companies, Ltd.
Vic Colwell, Treasurer
Vice President, Sales & Marketing
Loren Cook Company
Art LaPointe
George Atkinson, Director At Large
President
Hartzell Fan Company
Vice President and General Manager, Construction Specialties Inc.
Barbara L. Morrison, Executive Director
AMCA International
Stephen “Dane” Carey, Director
Director of Engineering
United Enertech Corporation
2009-2010 President, AMCA International
feature articles
departments
Patrick Cockrum, Director
President,
Pottorff
5The Role of Fan Efficiency in Reducing HVAC
Energy Consumption
A new fan efficiency grading system can help designers
3President’s
Message
John Knapp, Director
Vice President - Marketing & Sales
Ruskin Company
4News
Mike Pijar, Director
General Manager
Berner International Corporation
Dr. Geoff Sheard, Director
Director of Engineering
Flakt Woods, Ltd.
Gary Stroyny, Director
Executive Vice President & CFO
Greenheck Fan Corporation
C.F. Yang, Director
Executive Vice President & CFO
Kruger Ventilation Industries Pte Ltd.
select high-efficiency fans to help reduce overall
energy use. By Dr. Michael Brendel
11 Dampers: An Essential Component of
Fire Protection Design
15 Calendar
Automatic fire and/or smoke dampers and automatic fan
shutdown in HVAC systems are effective in preventing
the migration of smoke, flame, and heat during a fire.
By Vickie Lovell
AMCA International, Inc. is a not-for-profit association of the world’s manufacturers of related air system
equipment. For over 80 years, it has led the way in standards development and application research.
W W W. A M C A . O R G
A M C A I N T E R N AT I O N A L
inmotion
AMCA
NEWS
SPRING 2010
P U B L I C AT I O N U P DAT E S
Product Rating Manual for Acoustical Duct Silencers
Energy Efficiency Classification for Fans
AMCA International reaffirmed AMCA publication 1011-03, a Certified
Ratings Program Product Rating Manual for Acoustical Duct Silencers, and
provides a program for certifying a product’s sound dynamic insertion loss,
airflow generated noise, and pressure drop performance ratings.
Products that can be licensed by AMCA to bear the AMCA Certified Ratings
Seal are prefabricated acoustical duct silencers. Prefabricated acoustical
duct silencers are defined as silencers that are constructed in advance, or
manufactured in standard assemblies or sections ready for field installation.
The program applies to acoustical duct silencers within the scope of
AMCA International for which performance rating catalogs are published and
made available to the public. When performance ratings for both licensed and
unlicensed products are contained in the same catalog, a clear distinction must
be made between licensed and unlicensed products, as required in Section
11 of AMCA International Publication 11, Certified Ratings Program Operating
Manual.
When licensed products are used as component parts of a larger unit, the
AMCA International Certified Ratings Seal shall not be applied to the complete
unit. The seal can only be applied to the individually licensed components.
The Air Movement and Control Association International, Inc. (AMCA
International) announced that AMCA STANDARD 205-10, Energy
Efficiency Classification for Fans, was approved by the AMCA International
membership on February 19, 2010.
This standard defines the classification for all fan types designed to be
driven by motors of nominal rating
125 W (1/6 hp) and above. The fans
can range from the purpose-built
single fan to series-produced fans
manufactured in large quantities.
This standard applies to the fan
and not to the fan system, and
it excludes classification for
circulating fans.
This standard may be used
by legislative or regulatory
bodies for defining the energy
efficiency requirements of fans
used in specific applications.
Laboratory Methods for Testing Actuators
AMCA International announced that the Board of Standards
Review of the American National Standards Institute (ANSI) approved the
following document on December 2, 2009: ANSI/AMCA STANDARD 52009, Laboratory Methods for Testing Actuators. This standard establishes
an industry standard for minimum rating and testing of actuators used on
fire/smoke dampers. The testing requirements for ANSI/AMCA Standard
520-09 will cover torque or force rating, long-term holding, operational
life, elevated temperature performance, periodic maintenance, production,
and sound testing for both pneumatic and electric operators.
Application Manual for Airflow Measurement Stations
AMCA International has reaffirmed AMCA 600-06, Application Manual
for Airflow Measurement Stations, which provides important points to be
considered when designing or specifying HVAC and other applications
in installations requiring airflow measurement stations (AMS) for use in
temperatures from -30 C to +120 C (-20 F to +250 F), pressures to 250
Pa (10 in. wg), and velocities to 28 m/s (5,500 fpm).
The AMCA 600-06 manual is intended to assist designers and
users with proper application, performance considerations, selection,
and limitations of airflow measurement stations. This guide provides an
overview of permanently installed airflow measurement stations and their
application. Such information is not readily available in current texts on
HVAC or ventilation system design and will help designers to avoid typical
problems, including incorrect location, inappropriate measurement range,
mismatched accompanying instrumentation, AMS incompatible with the
intended application, and the like.
All AMCA publications are available at www.amca.org/store/
default.aspx
4
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A M C A I N T E R N AT I O N A L
BY DR. MICHAEL BRENDEL,
LAU INDUSTRIES/RUSKIN COMPANY,
DAYTON, OHIO
in Reducing HVAC Energy Consumption
A new fan efficiency grading system can help designers select high-efficiency
fans to help reduce overall energy use.
I
n 2008, the United States consumed about 100 quadrillion
BTU (106 EJ) of source energy to power everything from
lightbulbs to automobiles. That is the equivalent of over
29 million kWh, or a per capita energy consumption rate
of 11 kW. The vast majority of this energy comes from a limited
supply of nonrenewable resources. This has led many industries
to implement far-reaching initiatives and policies to address
energy conservation, and the HVAC industry is no exception.
The annual energy consumption for heating and cooling
of commercial buildings is estimated at 5 quadrillion BTU
(5.3 EJ). About one-third of this energy is used by the supply,
return, and exhaust fans. While this estimate represents a
small fraction of overall energy consumption, responsible
energy awareness and management at all levels is necessary to
achieve long-term energy reduction goals. This article reviews
the energy requirements of HVAC air distribution systems and
shows how a new fan efficiency grading system, embodied in
standard AMCA 205, will play a role in assuring energy-smart
fan selections. See the related news story on the recent passage
of AMCA 205 on Page 4.
ENERGY REQUIREMENTS
A typical HVAC distribution system includes a network
of ductwork, coils, filters, dampers, diffusers, and many
other specialized components. Airflow through these devices
encounters resistance, in the form of a pressure drop, which must
be overcome by adding energy to the flow. This energy can be
separated into potential and kinetic components, corresponding
to the static and velocity pressure. The total energy, or total
pressure (Pt) by analogy, is the sum of the two components:
potential plus kinetic. Static pressure (Ps) and velocity pressure
W W W. A M C A . O R G
Fan Efficiency
inmotion
The Role of
(Pv) can be traded back and forth in a duct system, so both
need to be correctly accounted for when considering energy
consumption. Ignoring compressibility effects, the rate at which
energy must be added to maintain a prescribed airflow rate is
the total pressure drop multiplied by the flow rate. This is called
the air power and in I-P units it is calculated as Ho = PtQ/6362
where Ho is the air power (hp), Pt is the total pressure drop
(in-wg), and Q is the flow rate (cfm). Although the air power
must be provided by the fan, it is important to recognize that
the required air power is a result of system design and does not
depend on the fan selection. A clear goal in reducing HVAC
system energy consumption is to minimize the required air
power through proper design of the air distribution system; that
is, minimize the system pressure drop and/or the flow rate. This
responsibility rests with the system designer and is the first step
in achieving energy reduction.
Specifying an energy-efficient fan can go a long way
toward reducing energy consumption, but it is not a sufficient
requirement. A poorly designed air distribution system with a
high total pressure drop might utilize a high-efficiency fan, but
the net energy consumption could be higher than a properly
designed system with low total pressure drop, utilizing the
same fan. One way to assure good system design is to specify
a maximum allowable air power per unit flow rate, H o /Q. This
effectively places an upper limit on the system pressure drop,
Pt. A variation of this approach is currently used in the ASHRAE
90.1-2007 standard to encourage good system design.
FAN EFFICIENCY
Figure 1 is a Sankey diagram showing the energy flow
through a fan system. A typical fan system consists of a motor,
5
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inmotion
SPRING 2010
W W W. A M C A . O R G
A M C A I N T E R N AT I O N A L
Fan shaft power
Fan aerodynamic loss
Motor output power
Fan bearing loss
mechanical losses (e.g., bearings), and, to a much
lesser extent, acoustic losses. The total efficiency
Mechanical
Air
of the fan is given by the ratio of air power to fan
Fan
Input
Motor
drive
Motor
power
power controls
shaft power.
Establishing energy-efficiency goals for
fans
presents a number of challenges. Fan
Fan acoustic loss
Drive losses
total
effi
ciency is a function of many variables
Motor losses
Control losses
including fan type, airflow, speed, and impeller
size. For example, HVAC fans are often designed
Figure 1. Fan energy flows from left to right through a typical fan system.
as a product series that includes multiple sizes
to meet different airflow requirements. Fans
within
the
series
generally have geometric similarity whereby
motor control, mechanical drive, and the fan. Power flows from
key dimensions scale in direct proportion to the fan impeller
left to right, with each component rejecting a portion of the
diameter. However, it is well known that smaller HVAC fans do
input energy as a result of inefficiencies. Energy efficiency of
not perform as well as larger fans from the same series. This is
each component is the ratio of the output power to the input
due to practical limits in manufacturing tolerances, aerodynamic
power. The fan imparts energy to the air stream by converting
effects, and disproportionate mechanical losses that occur as the
mechanical power at the fan shaft to air power at the outlet.
fan size is reduced.
Some of the input energy is rejected due to aerodynamic losses,
R
2570 AMCA Supplmnt Grn Ad indd 1
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A M C A I N T E R N AT I O N A L
FEG 85
FEG 80
FEG 75
FEG 71
FEG 67
FEG 63
FEG 60
FEG 56
FEG 53
FEG 50
80
70
60
50
inmotion
40
30
20
0
5
10
15
20
25
30
Impeller Diameter (in)
35
40
W W W. A M C A . O R G
Over the past several years, fan industry leaders within the
AMCA and ASHRAE communities have developed a simple
metric to classify fans by their energy efficiency: the Fan
Efficiency Grade (FEG). The FEG has been proposed in draft
standards AMCA 205 and ISO 12759, and offers code/regulatory
bodies a tool for specifying fan energy-efficiency targets.
The FEG for a given fan is determined from the peak total
efficiency (pTE) and the impeller diameter using the curves
shown in Figure 2. These curves are constructed so that fans in
a given geometric series should all have the same FEG regardless
of fan size. The FEG is established by plotting the impeller
diameter and peak total efficiency, then reading the associated
FEG band in which this point falls. For example, a fan with an
impeller diameter of 15 in and a peak total efficiency of 71%
would have an FEG of 80.
The FEG applies to a fan without any drive components. It
is customary in many parts of the world for manufacturers to
sell fans without motors or drives. Selection of efficient motors,
Peak total efficiency, pTE (%)
90
45
Figure 2. Fan Efficiency Grade curves are used to classify fans
by their energy efficiency.
controls, and drive systems is left to the buyer, which provides
flexibility in designing custom HVAC products. This also places
the responsibility for achieving higher FEGs directly in the
hands of the fan manufacturers. More details concerning the
HIGH PERFORMANCE. ENERGY EFFICIENT.
High performance buildings require high performance products. Ruskin
Green Products are AMCA Certiﬁed or fully tested in our AMCA Accredited
Laboratory. From Sunshades reducing thermal loads on the outside of the
building to Value-Flo balancing dampers providing the correct amount
of air at the branch take-off, we have the energy efﬁcient solution for you.
To learn more about Ruskin Green products, or to locate a representative
nearest you, visit our website at www.ruskin.com or call us at (816) 761-7476.
3900 Dr. Greaves Rd • Kansas City, MO 64030
(816) 761-7476 • Fax (816) 765-8955
Email: [email protected]
R
Specified By Many – Equaled By None
3/19/10 2:51 PM
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␩t(%)
500,000
10
points
␩t
Pv
Annual energy consumption (kWh)
pTE
Pt
Total pressure, Pt (in. wg), Total efficiency,
W W W. A M C A . O R G
A M C A I N T E R N AT I O N A L
inmotion
SPRING 2010
400,000
Pt = 8 in wg
300,000
Figure 3. This diagram depicts a typical fan curve
and the proposed 10-point total efficiency band.
Table 1. Selections for 25,000 cfm @ 6 in-wg (total pressure)
SPEED
(RPM)
SHAFT
POWER
(HP)
TE
pTE
DIFFERENCE
FAN SIZE
22
2507
36.1
65.6%
78.0%
12.4%
25
1992
31.7
74.6%
80.0%
5.4%
27
1656
29.2
80.9%
82.0%
1.1%
30
1399
28.3
83.5%
83.5%
0.0%
33
1247
29.4
80.3%
83.5%
3.2%
36
1138
31.6
74.7%
84.0%
9.3%
40
1044
33.8
69.9%
84.0%
14.1%
history, development, and scope of the FEG may be found in a
previous article.
The FEG is not the fan efficiency. It is a classification that
represents the energy efficiency potential of a fan. It is the
responsibility of the system designer to properly select fans to
best suit the needs of the application. Future regulations may
place a lower limit on acceptable FEG as part of an overall
strategy to reduce fan energy consumption. However, this alone
Pt = 4 in wg
100,000
Best total efficiency
Acceptable
Unacceptable
0
Flow rate
Pt = 6 in wg
200,000
22
25
27
30
33
Fan size (in)
36
40
Figure 4. This chart shows examples of fan selections in terms
of annual energy consumption.
will not guarantee that fans are properly selected. Per AMCA
205, codes that specify a minimum FEG must also require that
fan selections be within 10 points of the peak total efficiency.
This additional requirement assures high-efficiency operation
and helps place emphasis on total operating cost, rather than
first cost.
But how restrictive is the 10-point limit on fan selection?
FAN SELECTION
Figure 3 shows a typical fan curve with both the total pressure
and efficiency characteristics as well as the proposed 10-point
total efficiency band. For most common fan types (DWDI Airfoil,
plenum, DWDI forward curved, etc.), approximately 50% of the
fan capacity is available for selection. This is often comparable
to the manufacturer’s recommended selection range.
By way of example, consider an air handler that delivers
25,000 cfm (42,500 m3/h) at 6 in-wg (1,500 Pa) total pressure.
Selections were obtained from a series of belt-drive double-wide
airfoil fans having a FEG of 85. Table 1 shows several selections
meeting the performance target along with required shaft power
and total efficiency. Five of the seven selections are acceptable
based on the 10-point efficiency requirement.
Taking this one step further, Figure 4 shows the selections
in terms of annual energy consumption. Here it is assumed
that the motor and mechanical drive efficiencies are both 90%
8
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DR. MICHAEL BRENDEL is vice president
of Lau Industries/Ruskin Company.
A M C A I N T E R N AT I O N A L
inmotion
Volumetric flow rate (design requirement)
Intake louver
Control damper
Ductwork
Terminal
Diffuser
W W W. A M C A . O R G
“
“
The FEG is not the
fan efficiency. It is
a classification that
represents the energy
efficiency potential of
a fan.
Fan
Balance damper
Filter
Coil
System resistance (design result)
A typical HVAC air distribution system consists of a variety of a/c and air
control elements. The flow rate is a design requirement, while the system
resistance is the result of component selection and design calculations.
and that the duty cycle for the fan is continuous. This plot also
shows the importance of minimizing the system restriction by
considering the same 25,000 cfm flow requirement for 8 inwg (2,000 Pa) and 4 in-wg (1,000 Pa) systems. In both cases,
several fan sizes meet the 10-point restriction, although the fan
size for best performance increases with decreasing pressure
requirement.
The number of available selections offers the system designer
reasonable flexibility in selecting a fan size to meet other design
requirements. For example, further energy reductions are
possible with a VAV (variable air volume) system where fan
speed is modulated based on a duct pressure signal. The fan
must be selected to assure efficient operation and acceptable
turndown to meet multiple flow conditions. This requires
careful consideration of the fan operating schedule to determine
the net energy consumption at each operating point. In some
instances, this may lead to a fan size that is smaller than that
selected for continuous operation.
SUMMARY
Energy consumption of HVAC systems is garnering much
attention on both national and international fronts. Achieving
energy reduction goals in HVAC air distributions systems can
be accomplished on several levels. Designing systems that
minimize pressure drop for a given flow requirement must be
the first priority in reducing energy consumption. Selection
of high-efficiency fans that operate near peak efficiency
complements good system design and contributes to overall
energy reduction.
The FEG, a new fan energy-efficiency classification that has
been proposed in AMCA 205 and ISO 12759, offers a simple
metric for code and regulatory bodies to formulate new energy
standards for fans. The added requirement for selecting and
operating fans within 10 points of peak total efficiency assures
meaningful energy conservation without over-restricting system
design options.
REFERENCE
1. Annual Energy Review. DOE/EIA-0384. U.S. Energy Information Administration.
2009.
2. Westphalen, D., and S. Koszalinski. Energy Consumption Characteristics of
Commercial Building HVAC Systems, Vol. II: Thermal Distribution, Auxiliary
Equipment, and Ventilation. DOE/BTX. October 1999.
3. ASHRAE/ANSI/IESNA Standard 90.1: Energy Standard for Buildings except
Low-Rise Residential Buildings. ASHRAE. Atlanta, 2007.
4. Brooks, J., J. Cermak, and J. Murphy. Fan Industry Meeting Energy
Challenges. AMCA Inmotion Spring 2009.
9
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3/29/2010 2:09:39 PM
•
•
•
•
•
•
•
•
Fan Airflow Performance
Fan Energy Efficiency
Fan, Louver and Duct Silencer Sound Performance
Damper, Louver, and Duct Silencer Pressure Drop Performance
Damper and Spiral Duct Leakage Performance
Effectiveness of Louvers against Water Penetration
Louver Performance against Wind Driven Rain
Airflow Measuring Accuracy
Fans and Systems for
System Effect Factors
Quantifies the effects of
duct system design on
fan performance.
Visit www.amca.org for Certified Ratings Program information.
Assure your Green Building with AMCA Certied Products!
AIR MOVEMENT AND CONTROL
ASSOCIATION INTERNATIONAL, INC.
30 West University Drive
Arlington Heights, IL 60004-1893 U.S.A.
Tel: (847) 394-0150 • Fax: (847) 253-0088
E-mail: [email protected] • Web: www.amca.org
BY VICKIE LOVELL,
SPRING 2010
INTERCODE INC.,
DELRAY BEACH, FLA.
A M C A I N T E R N AT I O N A L
inmotion
W W W. A M C A . O R G
DAMPERS:
An essential component of
fire protection design
Automatic fire and/
or smoke dampers
and automatic
fan shutdown in
HVAC systems
are effective in
preventing the
migration of smoke,
flame, and heat
during a fire.
B
ased on an examination of NFPA data in the 1930s, in 1939 the National
Board of Fire Underwriters recommended that dampers be installed in
HVAC systems to interrupt the passage of smoke, flame, and heat during a
fire. Since that time, numerous experts in the field of the fire sciences have
substantiated the effectiveness of automatic closing fire and/or smoke dampers and
automatic fan shutdown in HVAC systems in preventing the migration of smoke,
flame, and heat to areas of a building remote from the area of origin. Throughout the
world, fire protection engineers and mechanical engineers continue to incorporate
fire and/or smoke dampers into the fire protection design of many types of modern
buildings.
CODE REQUIREMENTS
A fire damper is a device, installed an HVAC system, that closes automatically upon
the detection of heat in accordance with UL standard 555. A smoke damper is a device
11
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A M C A I N T E R N AT I O N A L
W W W. A M C A . O R G
“
The International
Code Council (ICC)
voting membership
has consistently
rejected proposals
to entirely remove
smoke dampers from
duct penetrations
from shafts.
installed in an HVAC system to control the
movement of smoke in accordance with UL
555S. Combination fire/smoke dampers fulfill the function of both fire and smoke dampers, and must meet the testing requirements
of both.
In the United States, the legacy model
codes contained provisions for requiring construction capable of resisting smoke spread.
Some of those requirements included the installation of smoke dampers. The 2000 Edition of the International Building Code (IBC)
retained the requirement for smoke dampers
in corridor walls when the corridor has a fire resistance rating
in language similar to the legacy codes.
But the 2000 IBC added a new requirement that requires
smoke dampers at the penetration of shaft enclosures in lieu of
requiring engineered smoke control systems, which had also
been mandatory under certain conditions in two of three of the
legacy codes. This code change was accepted in the new IBC
on the basis that many of the previously required fire-rated and
smoke-resistant floor and wall requirements in the legacy codes
were permitted to be weakened or eliminated when automatic
sprinklers were installed.
Because smoke dampers installed in duct penetrations of
shaft enclosures is a relatively new building code requirement,
and despite the concern about smoke spread throughout
buildings (including sprinklered buildings), the requirement for
smoke dampers in duct penetrations of shafts has been under
attack in every IBC change cycle since 2000. The opponents
of smoke dampers have previously cited the installed cost
and maintenance cost of smoke dampers as an “unreasonable
expense” to building owners, without increasing the safety of
the building occupants. The debate will occur again during the
hearings for the public comment on FS 113 May 18 to 19 in
Dallas at the ICC Final Action hearings for the 2012 IBC.
The reliability and effectiveness of sprinklers is often cited as
a justification for removing the requirement for smoke dampers
in shafts. The International Code Council (ICC) voting membership has consistently rejected proposals to entirely remove
smoke dampers from duct penetrations from shafts. Although
the ICC has voted to support some revisions since the proposal
was approved, it still applies to many buildings. However, the
valid question remains as to the cost benefit of smoke dampers
in shafts in sprinklered buildings.
AMCA RESEARCH
In 2008, the Air Movement and Control Assn. International
(AMCA) contracted with Koffel Assocs. Inc. to conduct a literature
search to identify credible work on this subject, and to use the
research findings (if any) as the basis for additional computer
modeling. The literature search resulted in two
interesting findings:
First, no documents were found that
would support the removal of smoke dampers
in shaft penetrations. On the contrary, the
literature search provided a sampling of fires
from the past 25 years where smoke spread
was an issue for occupant life safety. Many of
the fires occurred in occupancies in which
at least some of the legacy building code
requirements would not specifically have
required smoke dampers but would have
required construction capable of preventing
smoke spread, which could have included dampers. The data
collection methods from the time period studied would not
have specified when smoke dampers would have been required,
or even if they had been provided as an above-code provision.
Second, the literature search identified a relatively recent
modeling effort and some full-scale fire tests on the vertical
spread of smoke in buildings via shafts. The additional
modeling research, which has been contracted to be completed
by Koffel Assocs., expands on these two studies in an attempt
to better quantify the benefit of smoke dampers at duct
penetrations of shafts in sprinklered buildings. (The report on
the research and modeling conducted by Koffel Assocs. was
nearing completion at the time of this article’s printing, and
will be available in the near future through AMCA’s website at
www.amca.org.)
“
inmotion
SPRING 2010
THE SPRINKLER RELIABILITY DEBATE
At the heart of every debate in the decision to eliminate a
fire or smoke protection feature in order to offset the expense
of automatic sprinklers are two issues: reliability of automatic
sprinkler systems and their relative cost/benefit. The fact that
sprinkler systems fail to perform satisfactorily from time to time
is not debated. However, the frequency and the causes of such
failures stir controversy. When such malfunctions occur, a fire
that would have been a nuisance can quickly become a potential
catastrophe.
Sprinkler reliability figures are tossed about casually to
promote their installation without much consideration given
to the consequences of sprinkler failures in buildings where
many other features have been eliminated. In 2009, NFPA’s John
Hall authored the report, “U.S. experience with Sprinklers and
Other Automatic Fire Extinguishing Equipment.” The fire data
used to support the study was gathered from 2003 through
2006. In the study, Hall states that “automatic sprinklers
are highly effective elements of total system designed for
fire protection in buildings with sprinklers cover the area of
origin, they do they operate in 95% of all reported structure
fires large enough to activate sprinklers. When they operate,
12
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IN A
FIRE,
THE HIGHEST RISK TO LIFE
IS
SMOKE.
AIR MOVEMENT AND CONTROL
ASSOCIATION INTERNATIONAL, INC.
www.amca.org
A M C A I n t e r n a t i o n a l , 3 0 W. U n i ve r s i t y D r i ve, A r l i n g t o n H e i g h t s, I L 6 0 0 0 4
Phone: 847-394-0150
SPRING 2010
Vickie Lovell is the president of Intercode Inc., Delray Beach, Fla.
W W W. A M C A . O R G
A M C A I N T E R N AT I O N A L
inmotion
Intercode specializes in national model building code development and
consulting for companies with commercial markets that are affected by
building codes and standards.
they are effective 96% of the time, resulting in a combined
performance of operating effectively in 91% of reported fires
were sprinklers was present in the fire area and the fire was
large enough to activate.”
In 1997, an NFPA study examined fire data from 1986 to
1995 to evaluate the extent of flame and smoke spread in sprinklered and nonsprinklered buildings. For high-rise buildings
(seven stories or taller), the study showed that 11.4% of fires
in sprinklered buildings resulted in smoke damage beyond
the fire floor, while 15.4% of fires in nonsprinklered buildings
resulted in smoke damage beyond the fire floor. For mid-rise
buildings (three and six stories), 15.7% of fires in sprinklered
buildings resulted in smoke damage beyond the fire floor
while 34.4% of fires in nonsprinklered buildings resulted in
similar damage.
While the study was unable to define the severity of the
smoke damage or toxicity, it is significant that so many fires
in sprinklered buildings had smoke damage beyond the fire
floor. If smoke dampers were to be eliminated in sprinklered
buildings, and the automatic sprinkler systems failed for
whatever reason, the spread of smoke during fires would almost
certainly increase.
It is important to note that neither NFPA report supports
the position that sprinkler systems eliminate smoke, or that
fires that are controlled by sprinklers do not continue to
smoke production. G. W. Mullholland’s paper entitled “Smoke
Production and Properties,” recorded in the 1995 SFPE
Handbook of Fire Protection Engineering, estimated that if the
airborne soot particulates produced by burning an upholstered
armchair filled with 9 lbs of polyurethane foam were uniformly
distributed throughout 1,800-sq-ft room, a person would not
be able to see his or her own hand held at arm’s length in front
of his or her face. Even when sprinklers successfully suppress a
fire, the fire can be expected to continue to burn and produce
soot particulates and toxic gases.
Numerous studies have been conducted on fires where the
sprinklers’ water spray was shielded by some obstruction and
never reached the item that was burning. Such fires effectively
became nonsprinklered fires.
Experts confirm that automatic sprinkler systems are very
effective, although not infallible or a panacea. The sprinkler industry, the fire service, and the fire protection community are
continually striving to improve sprinkler reliability when the
causes of sprinkler failure become known. John Klote, in an
article entitled “Compartmentation and Dampers are Essential,”
stated, “in our ever-changing organizational functions, materials, construction methods, and architectural designs, it is reasonable to expect that new failure situations will arise. For that
reason, sprinklered buildings need other fire (and smoke) protection features to ensure an adequate level of protection in the
event of sprinkler failure.”
Additionally, damper manufacturers, contractors, installers,
and the fire service are cooperating to ensure that the dampers
are both installed correctly and periodically inspected to ensure
functionality.
Building codes can control the construction materials used
in a building, which is taken into consideration when sprinkler systems are designed. However, neither building codes nor
designers can control the materials that occupants bring into
the building. If the wrong types of materials are brought into
a building a sprinkler system that would otherwise control a
fire can be easily overwhelmed. Therefore, sprinkler systems are
best supported by designs, systems, and devices such as smoke
dampers that help to manage smoke migration, even during
successful sprinkler activation.
CONCLUSION
There is little debate as to whether an HVAC system can
transport smoke to areas remote from the fire area’s origin.
However, there is still some debate as to how best to manage the
smoke in both sprinklered and nonsprinklered fires. For many
years, system shutdown was the standard approach to achieving
some control over smoke migration.
Since 2000, however, the operation of the HVAC system
in smoke control mode is not required in most buildings constructed to the IBC. Without an engineered smoke control
system, or complete system shutdown and functional smoke
dampers at shaft penetrations, the HVAC system can transport
smoke to every building area the system serves. Even shutting
down the HVAC system without dampers will not prevent it
from supplying oxygen to the fire and will not entirely prevent
smoke movement throughout the HVAC system.
The installation of smoke dampers at the shaft penetration
by the duct can help inhibit smoke movement through the
HVAC system.
REFERENCES
1. Koffel Assocs. Inc. 2009. “Literature Search of Smoke Damper
Performance for Air Movement and Control Assn. International Inc.,”
Elkridge, Md.
2. Koffel Assocs. Inc. 2009. “Smoke Damper Evaluation for Air Movement and
Control Assn. International Inc.,” Elkridge, Md.
3. Mullholland, G. W. 1995. “Smoke Production and Properties.” SFPE
Handbook of Fire Protection Engineering, Quincy, Mass.
4. Klote, John H. 2004. “Compartmentation and Dampers are Essential.” John
H. Klote Inc. Leesburg, Va.
5. Klote, John H. 1993. Air Moving System and Fire Protection. U.S. Dept. of
Commerce, NIST. Gaithersburg, Md.
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AMCA
SPRING 2010
NEWS
A M C A I N T E R N AT I O N A L
AMCA International’s 2010 Event Calendar
AHR Expo Mexico
Mexico City
October 26-28, 2010
China Refrigeration Expo
Beijing, China
April 7-9, 2010
AMCA European Region Meeting
Lyon, France
April 12–14, 2010
Big 5
Dubai, UAE
November 22-25, 2010
AHR Expo
Las Vegas
January 31- February 2, 2011
AMCA Midyear Meeting
Elk Grove Village, Ill.
May 2–3, 2010
U.S. Green Building Council
(USGBC Greenbuild)
Chicago
November 16-18, 2010
AMCA International 56th Annual Meeting
Grand Hyatt Kauai Resort & Spa,
Hawaii
October 19-22, 2011
NFPA
Las Vegas
June 7-9, 2010
W W W. A M C A . O R G
AMCA International 55th Annual
Meeting
Fairmont Turnberry Isle Resort &
Club
Aventura, Fla.
October 14–17, 2010
inmotion
AMCA Pacific Rim Region Meeting
Beijing, China
April 8, 2010
AIA
Miami
June 10-12, 25010
ad index
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PAGE NO.
PHONE NO.
WEBSITE
AMCA International, Inc.
11, 13
847-394-0150
www.amca.org
Greenheck Fan Corp.
16
715-359-6171
www.greenheck.com
Loren Cook Company
2
417-869-6474
www.lorencook.com
Mars Air Systems
4
800-421-1266
www.marsair.com
Ruskin
6, 7
816-761-7476
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cse1004_Amca_Cal_AdIndex.indd 15
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